Process for separating precious metals from their ores.



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WI IAM HENRY AGI'IAN, or BURKES FLAT, vrcronre, nusrnenrn.

PBOCESS FOR SEPARATING PRECIOUS. IMETALSFROEJE TEEIE GEES.

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tain new and useful Improvements in Processes for Separating PreciousMetals from Their Ores; and I do declare the following to be a full,clear, invention such as will enable others skilled in the art to whichit appertains to make and use the same.

The object of this invention is to provide an improved process andchemical means to be used in such process, for the recovery of preciousmetals from sands, tailings, the residues of batteries, and slimes oralluvial containing coarse or fine gold.

In the past a comparatively low return of gold has been obtained by themercurial amalgamation system of treatment when applied to auriferousparticles in tailings and the like owing to the surfaces of the metalconstituents having become oxidized, smeared with earthy matter, orchemically coated with suflicient foreign matter to prevent the metalfrom coming into intimate contact with the mercury.

My invention embodies the employment of certain chemical means whichwill remove the above-mentioned disadvantage from the gold constituentsin the ores or tailings and render them highly amenable to theamalgamating influence of the quicksilver. The said chemicals also exerta cleansing effect on the mercury by removing superficial impuritiestherefrom and thus cuickening its properties.

I shall now means employed therein when treating bearing sands orslimes.

A desired quantity of the auriferous material is fed either into a vator agitator and immersed in a thoroug ily mixed chemical solution, thequantity of which is suflicient to saturate the sands or slimes duringtreatment. Such solution is used in varying strengths, one consistingapproximately of one hundred gallons of water to which is describe theprocess and goldadded cyanid of potassium to make same test .1% (pointone per cent.) KCN. Sulfuric acid is now added at the rate of twentycubic centimeters to each one hundred gal- Specification of LettersPatent.

and exact descriptlonof the,

Patented Jan, 2, 191?.

Application filed December 9, 1914. Serial No. 876,350;

lens of solution. Twenty-four penny weights of corrosive sublimate, andforty-eight penny weights of common salt are then added and the solutionis thoroughly mixed.

, The sands or slimes to be treated are first put into a vat or agitatorandsuiiicient solution run on to thoroughly immerse same, either bypercolation or agitation for a suitable length of time, preferably notless than ten minutes, and longer according to the class of sand orslime under treatment.

Sufficient water is now added to the mixture to bring it to a liquidcondition, so as to allow the fine and coarse particles of gold toamalgamate in any suitable apparatus. By the addition of sulfuric acidbefore mentioned, the cyanid in solution is intensified in its cleansingpower, any impure matters, acid or metallic coating around the gold isdissolved and the precious metal is free and amenable to amalgamation.

The addition of the before mentioned corrosive sublimate has thetendency to coat and add extra weight to the very fine particles of goldand thus materially assists in the amalgamation. The addition of thebefore mentioned common salt acts as a precipitating agency to the sameend.

By experiment, I have found the solution very efiective in the followingstrengthscyanid of potassium from .1% (point one per cent.) KCN to 02%(point naught two per cent.) KCN. And sulfuric acid at the rate oftwelve cubic centimeters to ninetysix cubic centimeters to every onehundred gallons of solution.

The quantity of cyanid and sulfuric acid to be used in the solution'mustbe according to the nature of the sand or slimes being treated, forexampleif the ore does not contain acids (mineral) and is free, theweakest of my solutions will be used-The more complex the ore, thestronger the solution, until it reaches the strength as first given.When there are free mineral acids in the sand slimes or tailings to betreated, it is preferable to use sufiicient lime in same before addingthe solution, so that any free and mineral acids are neutralized, andthe ore sweetened, allowing the gold to become more amenable toamalgamation.

I reserve to myself the right to omit the cyanid of potassium from themixture when ter, sulfuric acid, corrosive sublimate, and

tions described, other reagents capable of tion of a bath containing asolution of Water, cyanid of potassium, sulfuric acid, corrosivesublimate, and common salt, in the approximate proportions described,other reagents capable of modifying the action on the bath beingexcluded. i V

2. In separating precious metals from their oressubjecting such ores tothe action of a bath containing a solution of Wacommon salt, in theapproximate propor- Uopi es of this patent may be obtained for modifyingthe action on the bath being excluded. 1

3. In separating precious metals from their oressubjecting the ores totreatment With'lime to neutralize the same, and then to a treatment Witha solution consisting of Water, cyanld of potassium, sulfur1c acld,corrosive sublimate, and commonsalt, other the bath being excluded.

In testimony 'WhereofI have} signed-my name to this specification in twosubscribing Witnesses.

WILLIAM HENRYV'AGHAN. WVitnesses:

AUGUSTINE THOMAS ALICE HARKE MADDEN,

five cents each, by addressing thev Commissioner of Patents, Washington,D. G. r

reagents capable of modifyingithe action on the presence of 3o

